Locomotive fire-box



j 1933- I G. L. BAXTER ET AL 00,

LOCOMOTIVE F IRE BOX Filed Oct. 18, 1930 GEORGE L. BAXTER Patented Mar. 7, 1933' UNITED STATES PATENT OFFICE AND FREDERICK W. STRACHAUER, OF SACRAMENTO, D RALPH S.

TWOGOOD, 0F BERKELEY, CALIFORNIA.

LOCOMOTIVE FIRE-BOX Application filed October 18, 1930.. Serial No. 489,566.

Our invention relates to locomotive fireboxes of the type adapted for burning fuel in fluid form.

The principal objects of the invention are to promote fuel efiiciency and minimize fuel consumption by providing for complete combustion of the fuel before entering the boiler flues, andto minimize excessive temperature strains within the fire-box, which result in leaky and broken stay-bolts and leaky flues, with consequently high maintenance expense and loss of use. These objects are achieved by introducing the air and mixing it with the fuel in such a manner that both are heated to combustion temperature before mixing occurs, and that thorough mechanical mixing is accom-' plished. Furthermore, the air is so directed that there are no relatively cold air currents in the fire-box which would result in localized areas of low temperature, and said air is automatically controlled according to the power output of the engine, so that there are no sudden and violent temperature fluctuations within the fire-box.

Other objects and advantages of the invention will become apparent from the following specification, which should be read with the understanding that changes, with-- in the scope of the claims hereto appended, may be made in the form, construction and arrangement of the several parts, without departing from the spirit of ,the invention as set forth in said claims.

A preferred embodiment of our invention will now be fully described with reference to the accompanying drawing, wherein Fig. 1 is a longitudinal central section of our fire-box and the rear portion of a locomotive boiler.

Fig. 2 is a transverse section taken on the line 2-2 of Fig, 1.

In the drawing, the reference numeral 3 designates the rear portion of a locomotive boiler of usual construction, having flues 4. The fire-box 5 is also mainly constructed according to usual practice, having crown sheet 6, rear wall 7 with fire-door 8, front wall or flue sheet 9, side walls 10, fire pan 11 with fire brick lining 12, and fire-brick flash wall 13. A burner 14, adapted to inject a jet of oil or other fuel in fluid form into the firebox, is positioned in the front wall of the fire-pan 11. The path of the fuel stream into and through the fire-box is indicated by the'arrows 15 in Fig. 1. An air opening 16, of limited area, is provided around the burner 14. This opening is of such size that only enough air enters through it to prevent over heating of the buf'ner tip, and to start combustion of the fuel stream 15. So much is usual locomotive construction.

At the rear of the fire-pan 11, just forward of the flash wall 13, we provide three air inlet openings. One, shown at 17, is in the longitudinal center of the fire-pan, and is controlled by a damper 18, which has a lever 19 adapted to be connected with any suitable manual operating means, not shown, within the control of the fireman. A shield or chute 20 below the aperture 17 prevents sparks and. pieces of hot brick from droppinglto the road bed beneath.

T e other two air inlet openings 21 are symmetrically positioned on the two sides ofthe inlet'17, and have interior flanges 22 to retain the brick-work and to direct the stream 15.

The air inlets 21 have exterior chutes 25 to prevent the dropping of sparks and hot pieces of brick, and are controlled by automatic or draft-operated flap dampers 26. These latter are positioned in the open upper sides of the chutes 25, to prevent clogging from pieces of brick which may drop into said chutes, and are pivotally mounted at 27 and normally held closed by weights 28 adjustably secured upon arms 29. The weights 28 are so adjusted that the dampers 26 will remain closed under natural draft conditions in the fire-box, i. e. when the engine is not working, but will open when forced draft occurs, due to the engine exhaust, as shown by the broken line position at the right of Fig. 2.

Inthe operation of a locomotive having our improved fire-box, suflicient air enters through the opening 16 around the burner to start combustion of the fuel, and by the.

time the fuel stream has traveled from the burner to the flash wall, its temperature has been raised by this partial combustion to a point at which complete combustion will occur upon'the admission of suflicient additional; air. a

In firing up the boiler, and when the engine is driftin i. e. when only a light fire is required, t e necessary additional air is admitted through the central'or auxiliary inlet 17 by opening the manually controlled damper 18. Under these conditions, there being no forced draft, the automatic dampers 26, controlling the side or main air inlets 21, remain closed. When the engine is -working, however and its exhaust sets up a forced draft in the fire-box, the automatic dampers 26 open, admitting a relatively large quantity of additional air, which rises in two converging streams across the face of the hot flash wall 13, thereby becoming heated, and intersects and mixes with the rising fuel stream at the point 24, at which 4 point com lete combustion occurs.

When t e engine throttle is closed,]the forced draft ceases, and the automatic dampers 26 immediately close thereby preventing an excessive amount of air from entering and cooling the fire-box. Thus. violent changes in tem erature are prevented.

The manual y controlled auxiliary air damper 18 ma be open or closed .when thewhen the main dampers are closed and a light: fire is to be maintained.-

It is to be noted that, with the exception of the small amount 'of air entering at 16 around the burner, and which is immedi-- ately heated and used by the partial combustion of the fuel stream, all the entering air passes over the face ofthe hot flash wall "'13, and is thereby heated before mixing with the fuel, so that there are no cold drafts within the fire-box, nor is said fuel cooled below the temperature necessary to complete combustion. 1 Furthermore, the intersecting from different directions, of the two main air streams 23 with the rising fuel stream, causes very complete mechanical mixing of air and fuel, and this, together with the maintenance of high temperatures of both air and fuel, enables satisfactory combustion to occur at or near the point 24:, and to be aeoaeae entirely completed before the ases enter the boiler flues. There is, there ore, no deposition of soot or carbon, and no waste offuel.

Thus our invention, by preventing-uneual temperatures and violent'temperature c anges within the fire-box, reducesmaintenance costs and loss of use; and by insuring complete combustion, prevents waste of fuel and further reduces maintenance costs ordinarily caused by the necessity of clean ing soot out of the fire-box and boiler flues.

We claim:

1. In a fire-box havin a flash wall at one end and a pair of latera ly spaced air inlets in its lower portion adjacent the face of said flash wall, a burner adapted to direct a stream of fuel substantially horizontally against the lower central portion of said flash wall, said fuel stream then rising along the face thereof, means for directin the air streams enterin and convergingly to a common intersection with the rising fuel stream; and automatic rising along the face thereof and intersecting said air streams, a manually operated damper for controlling one-- of said air streams; and an automatic damper responsive to draft conditions in the'fire-box for controlling another of said air streams.

3. In a fire-box having a. flash wall and three laterally spaced air inlets in its lower portion adapted, to direct intersectin streams of air upwardly over the face 0 said flash wall, a burner adapted to direct a stream of fuel against said flash wall, said fuel stream then rising along the face thereof and intersecting said air streams, a manually operated damper for controlling the central air inlet; and automatic dampers responsive to draft conditions in the firebox for controllin the side air inlets.

In testimony w ereof we have signed our names to this specification.

"GEORGE". L. BAXTER. RALPH S. TWOGOOD. I FREDERICK W. STRACHAUER.

through said inlets upwardly over the ace of said flash wall 

